681246720 has 544 divisors, whose sum is σ = 3019875840. Its totient is φ = 141557760.

The previous prime is 681246697. The next prime is 681246751. The reversal of 681246720 is 27642186.

It is a super-4 number, since 4×681246720⁴ (a number of 36 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 61931515 + ... + 61931525.

Almost surely, 2^681246720 is an apocalyptic number.

681246720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

681246720 is a droll number since its even prime factors and its odd prime factors have the same sum.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681246720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1509937920).

681246720 is an abundant number, since it is smaller than the sum of its proper divisors (2338629120).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

681246720 is an equidigital number, since it uses as much as digits as its factorization.

681246720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64 (or 28 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 681246720 is about 26100.7034387964. The cubic root of 681246720 is about 879.9030196157.

The spelling of 681246720 in words is "six hundred eighty-one million, two hundred forty-six thousand, seven hundred twenty".